Fluidized bed reactors (also referred to herein as the “reactor”) are widely used in industry to make a variety of products such as polyethylene and other polyolefins. One problem often encountered in using these reactors is uneven channeling of a feed through the bed of the reactor resulting in partial or even total loss of bed fluidization; significant loss of fluidization may result in sheeting or agglomeration in the bed and/or make reactor shutdown necessary.
Channeling problems have been remedied by the use of feed distributors. U.S. Pat. Nos. 4,933,149; 5,082,634; and 5,213,768 are illustrative of feed distributors known in the art.
One drawback of such feed distributors is the tendency for them to plug with solids formed in or otherwise introduced into the reactor and/or recycle loop. Uneven channeling can then appear in the associated fluidized bed with consequences as previously described.
Attempts to solve these drawbacks are disclosed in the following patents. In U.S. Pat. No. 4,933,149, a deflector plate and screen located inside the polymerization reactor and below the feed distributor are disclosed in the Description by Rhee et al. In U.S. Pat. No. 5,082,634 Raufast discloses a method for removal of solids from above the feed distributor. In U.S. Pat. No. 5,126,414 Cooke et al. discloses a method of substantially eliminating distributor plate fouling by removing oligomers from the recycle feeds to the fluid bed reactor.
In spite of these attempts, there exists a need for better solutions to the aforementioned channeling and feed distributor plugging problems. The present invention is directed to filling this need among others.